Abstract: The present invention relates to solid forms of the hydrochloride salt 3-[5-(4-methanesulfonyl-piperazin-1-yl-methyl)-1H-indol-2-yl]-1H-quinolin-2-one which inhibit, regulate and/or modulate tyrosine kinase signal transduction, compositions which contain these compounds, and methods of using them to treat tyrosine kinase-dependent diseases and conditions, such as angio-genesis, cancer, tumor growth, atherosclerosis, age related macular degeneration, diabetic retinopathy, inflammatory diseases, and the like in mammals.